In the prior art, there have been contrived various kinds of medical treatment diagnosis devices and methods thereof for removing such as a stenosis or occlusion of a blood vessel and an atheroma due to such as an arteriosclerosis.
A bypass operation is the most assured treatment method in which a lesion is completely removed by replacing a blood vessel including a diseased part with one of patient's own blood vessels or with an artificial blood vessel for example. However, since this method is followed by a surgery in which tissue is cut open, the vital body is subjected to a burden and a large amount of cost is needed for the treatment. Moreover, although a drug treatment is also adopted, it is effective only for solution of a thrombus and it has been difficult to remove an arteriosclerosis focus.
Therefore, there has been recently adopted a treatment that a catheter is inserted into a blood vessel from the outside of a body and the diseased part reached so as to directly remove a cause of an obstacle.
One is a treatment that a balloon catheter having a balloon attached on its distal tip portion is used and the balloon is expanded when the diseased part is reach so that the stenosis of the blood vessel is mechanically expanded. However, since the stenosis is simply expanded, e.g. the diseased focus of the arteriosclerosis or thrombus which causes a stenosis can not be removed and a probability of a relapse of a disease in a short period is high. Moreover, in cases where the blood vessel is entirely so occluded that the balloons can not be inserted and the arteriosclerosis is so advanced as to cause a calcification, it becomes difficult to treat by using a balloon.
The other is a method using laser light such as YAG laser or argon laser, wherein a metallic or ceramic chip attached to the tip of the catheter is heated by the laser light projected from the tip of an optical fiber so that the heated chip is pressed onto the diseased part so as to burn out the diseased part. According to this method, though the diseased part can be removed, the control of the light heating power is difficult and if the chip is overheated, a normal vessel wall is damaged or carbonized so that there may cause a new risk of vascular perforation or a new restenosis. Moreover, in case the vessel is tortuous or completely occluded, the chip method is not available because it can not be inserted.
Therefore, a method has been adopted in which the laser light from such as YAG laser, argon laser and excimer laser is directly projected onto the diseased part from the tip of the fiber so as to vaporize the diseased part. Since the portion having the laser light projected thereon is directly vaporized, the laser light is available also for a completely occluded diseased part and upon controlling the output of the laser light source and a pulse width and pulse interval of the pulse laser, a power control is possible with high accuracy.
In the intravascular laser operating device of a directly projecting type in the prior art as mentioned above, upon inserting the guide catheter up to the diseased part fibers and a tube necessary for diagnosis and treatment are alternately inserted.
For example, in the case of diagnosis and treatment of a diseased part in a vessel, first, endoscopic optical fibers and illumination optical fibers are inserted and a fixing balloon for occluding the blood vessel attached to the tip portion of the catheter is expanded so as to stop the blood flow, and liquid (flush liquid) having little loss in the range of the wave length of the laser light in use is charged and replaced with blood so that the condition in the blood vessel is displayed on the screen under the condition that the vision is made transparent. Subsequently, after the diagnosis of the diseased part is performed, the fibers are replaced with a laser light applying fiber and in this condition, the laser light is applied to remove the diseased part.
In such a method, however, since it is impossible to observe the diseased part when projecting the laser light, it has been difficult to confirm whether or not the projection is accurately performed. Accordingly, it has been difficult to secure the quickness, safety and sureness of the treatment.
Therefore, there is designed an intravascular laser operating device having a catheter accommodating endoscopic optical fibers, illumination optical fibers and laser light projecting fibers.
However, in this device, since the laser light is an invisible light with a wave length of such as ultraviolet or infrared range, it is impossible to confirm an accurate laser light projection position and there has been a problem that it is difficult to project the laser light only onto the diseased part accurately. Moreover, there has been a further problem that it is difficult to accurately confirm with only an endoscopic observation about the position of a diseased part or whether or not the diseased part is completely removed using the laser light, and whether or not there have been removed a tissue more than required.
The present invention has been made considering the problems mentioned above and has as its object to provide an intravascular laser operating device capable of accurately discriminating a diseased part and confirming the laser projection position and of performing a sure treatment.